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Latrous L, Salpin JY, Haldys V, Léon E, Correia C, Lamsabhi AM. Gas-phase interactions of organotin compounds with cysteine. JOURNAL OF MASS SPECTROMETRY : JMS 2016; 51:1006-1015. [PMID: 27428725 DOI: 10.1002/jms.3812] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 07/02/2016] [Accepted: 07/12/2016] [Indexed: 06/06/2023]
Abstract
The gas-phase interactions of cysteine with di-organotin and tri-organotin compounds have been studied by mass spectrometry experiments and quantum calculations. Positive-ion electrospray spectra show that the interaction of di- and tri-organotins with cysteine results in the formation of [(R)2 Sn(Cys-H)]+ and [(R)3 Sn(Cys)]+ ions, respectively. MS/MS spectra of [(R)2 Sn(Cys-H)]+ complexes are characterized by numerous fragmentation processes, notably associated with elimination of NH3 and (C,H2 ,O2 ). Several dissociation routes are characteristic of each given organic species. Upon collision, both the [(R)3 Sn(Gly)]+ and [(R)3 Sn(Cys)]+ complexes are associated with elimination of the intact amino acid, leading to the formation of [(R)3 Sn]+ cation. But for the latter complex, two additional fragmentation processes are observed, associated with the elimination of NH3 and C3 H4 O2 S. Calculations indicate that the interaction between organotins and cysteine is predominantly electrostatic but also exhibits a considerable covalent character, which is slightly more pronounced in tri-organotin complexes. A preferred bidentate interaction of the type -η2 -S-NH2 , with sulfur and the amino group, is observed. As for the [(R)3 Sn(Cys)]+ complexes, their stability is due to the combination of the hydrogen bond taking place between the amino group and the sulfur lone pair and the interaction between the carboxylic oxygen atom and the metal. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Latifa Latrous
- Laboratoire de Chimie Analytique et Electrochimie Campus Universitaire, Faculté des Sciences de Tunis, Université de Tunis El Manar, 2092, Tunis, Tunisia.
| | - Jean-Yves Salpin
- Laboratoire Analyse et Modélisation pour la Biologie et l'Environnement, Université d'Evry Val d'Essonne, Bâtiment Maupertuis-Boulevard François Mitterrand, 91025, Evry, France
- CNRS-UMR 8587, Evry, France
| | - Violette Haldys
- Laboratoire Analyse et Modélisation pour la Biologie et l'Environnement, Université d'Evry Val d'Essonne, Bâtiment Maupertuis-Boulevard François Mitterrand, 91025, Evry, France
- CNRS-UMR 8587, Evry, France
| | - Emmanuelle Léon
- Laboratoire Analyse et Modélisation pour la Biologie et l'Environnement, Université d'Evry Val d'Essonne, Bâtiment Maupertuis-Boulevard François Mitterrand, 91025, Evry, France
- CNRS-UMR 8587, Evry, France
| | - Catarina Correia
- Laboratoire Analyse et Modélisation pour la Biologie et l'Environnement, Université d'Evry Val d'Essonne, Bâtiment Maupertuis-Boulevard François Mitterrand, 91025, Evry, France
- CNRS-UMR 8587, Evry, France
| | - Al Mokhtar Lamsabhi
- Departamento de Química, Ciencias, M-13, Universidad Autónoma de Madrid, Campus de Excelencia UAM-CSIC Cantoblanco, 28049, Madrid, Spain
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Meng L, Lin Z. Complexations of alkali/alkaline earth metal cations with gaseous glutamic acid. COMPUT THEOR CHEM 2014. [DOI: 10.1016/j.comptc.2014.04.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Latrous L, Tortajada J, Haldys V, Léon E, Correia C, Salpin JY. Gas-phase interactions of organotin compounds with glycine. JOURNAL OF MASS SPECTROMETRY : JMS 2013; 48:795-806. [PMID: 23832935 DOI: 10.1002/jms.3223] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 03/08/2013] [Accepted: 04/22/2013] [Indexed: 06/02/2023]
Abstract
Gas-phase interactions of organotins with glycine have been studied by combining mass spectrometry experiments and quantum calculations. Positive-ion electrospray spectra show that the interaction of di- and tri-organotins with glycine results in the formation of [(R)2Sn(Gly)-H](+) and [(R)3Sn(Gly)](+) ions, respectively. Di-organotin complexes appear much more reactive than those involving tri-organotins. (MS/MS) spectra of the [(R)3Sn(Gly)](+) ions are indeed simple and only show elimination of intact glycine, generating the [(R)3Sn](+) carbocation. On the other hand, MS/MS spectra of [(R)2Sn(Gly)-H](+) complexes are characterized by numerous fragmentation processes. Six of them, associated with elimination of H2O, CO, H2O + CO and formation of [(R)2SnOH](+) (-57 u),[(R)2SnNH2](+) (-58 u) and [(R)2SnH](+) (-73 u), are systematically observed. Use of labeled glycines notably concludes that the hydrogen atoms eliminated in water and H2O + CO are labile hydrogens. A similar conclusion can be made for hydrogens of [(R2)SnOH](+) and [(R2)SnNH2](+) ions. Interestingly, formation [(R)2SnH](+) ions is characterized by a migration of one the α hydrogen of glycine onto the metallic center. Finally, several dissociation routes are observed and are characteristic of a given organic substituent. Calculations indicated that the interaction between organotins and glycine is mostly electrostatic. For [(R)2Sn(Gly)-H](+) complexes, a preferable bidentate interaction of the type η(2)-O,NH2 is observed, similar to that encountered for other metal ions. [(R)3Sn](+) ions strongly stabilize the zwitterionic form of glycine, which is practically degenerate with respect to neutral glycine. In addition, the interconversion between both forms is almost barrierless. Suitable mechanisms are proposed in order to account for the most relevant fragmentation processes.
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Affiliation(s)
- Latifa Latrous
- Laboratoire de Chimie-Analytique et Electrochimie, Département de Chimie, Faculté des Sciences de Tunis, Campus Universitaire, 2092, El Manar, Tunis, Tunisia.
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O’Brien JT, Prell JS, Steill JD, Oomens J, Williams ER. Changes in Binding Motif of Protonated Heterodimers Containing Valine and Amines Investigated Using IRMPD Spectroscopy between 800 and 3700 cm−1 and Theory. J Am Chem Soc 2009; 131:3905-12. [DOI: 10.1021/ja809928h] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jeremy T. O’Brien
- Department of Chemistry, University of California, Berkeley, California 94720-1460, and FOM Institute for Plasma Physics “Rijnhuizen”, Edisonbaan 14, 3439 MN Nieuwegein, The Netherlands
| | - James S. Prell
- Department of Chemistry, University of California, Berkeley, California 94720-1460, and FOM Institute for Plasma Physics “Rijnhuizen”, Edisonbaan 14, 3439 MN Nieuwegein, The Netherlands
| | - Jeffrey D. Steill
- Department of Chemistry, University of California, Berkeley, California 94720-1460, and FOM Institute for Plasma Physics “Rijnhuizen”, Edisonbaan 14, 3439 MN Nieuwegein, The Netherlands
| | - Jos Oomens
- Department of Chemistry, University of California, Berkeley, California 94720-1460, and FOM Institute for Plasma Physics “Rijnhuizen”, Edisonbaan 14, 3439 MN Nieuwegein, The Netherlands
| | - Evan R. Williams
- Department of Chemistry, University of California, Berkeley, California 94720-1460, and FOM Institute for Plasma Physics “Rijnhuizen”, Edisonbaan 14, 3439 MN Nieuwegein, The Netherlands
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Wang P, Ohanessian G, Wesdemiotis C. Cu(II)-catalyzed reactions in ternary [Cu(AA)(AA - H)]+ complexes (AA = Gly, Ala, Val, Leu, Ile, t-Leu, Phe). EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2009; 15:325-335. [PMID: 19423917 DOI: 10.1255/ejms.987] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The unimolecular chemistry of [Cu(II)AA(AA - H)](+) complexes, composed of an intact and a deprotonated amino acid (AA) ligand, have been probed in the gas phase by tandem and multistage mass spectrometry in an electrospray ionization quadrupole ion trap mass spectrometer. The amino acids examined include Gly, Ala, Val, Leu, Ile, t-Leu and Phe. Upon collisionally-activated dissociation (CAD), the [Cu(II)AA(AA - H)](+) complexes undergo decarboxylation with simultaneous reduction of Cu(II) to Cu(I); during this process, a radical site is created at the alpha-carbon of the decarboxylated ligand (H(2)N(1) - (*)C(alpha)H - C(beta)H(2) - R; R = side chain substituent). The radical site is able to move along the backbone of the decarboxylated amino acid to form two new radicals (HN(1)(*) - C(alpha)H(2) - C(beta)H(2) - R and H(2)N(1) - C(alpha)H(2) - (*)C(beta)H - R). From the complexes of Gly and t-Leu, only C(alpha) and N(1) radicals can be formed. The whole radical ligand can be lost to form [Cu(I)AA](+) from these three isomeric radicals. Alternatively, further radical induced dissociations can take place along the backbone of the decarboxylated amino acid ligand to yield [Cu(II)AA(AA - 2H - CO(2))](+), [Cu(I)AA((*)NH(2))](+), [Cu(I)AA(HN = C(alpha)H(2))](+), or [Cu(I)AA(H(2)N - C(alpha)H = C(beta)H - R'](+) (R' = partial side chain substituent). The sodiated copper complexes, [Cu(II)(AA - H + Na)(AA - H)](+), show the same fragmentation patterns as their non-sodiated counterparts; sodium ion is retained on the intact amino acid ligand and is not involved in the CAD pathways. The amino groups of both AA units, the carbonyl group of the intact amino acid, and the deprotonated hydroxyl oxygen coordinate Cu(II) in square-planar fashion. Ab initio calculations indicate that the metal ion facilitates hydrogen atom shuttling between the N(1), C(alpha) and C(beta) atoms of the decarboxylated amino acid ligand. The dissociations of the decarboxylated radical ions unveil important insight about the so far largely unknown intrinsic chemistry of alpha-amino acid and peptide radicals, which are implicated as intermediates in numerous pathogenic biological processes.
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Affiliation(s)
- Ping Wang
- The Dow Chemical Company, 2301 N. Brazosport Blvd, B-1219 Freeport, TX 77541-3257, USA
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Bush MF, Oomens J, Saykally RJ, Williams ER. Effects of Alkaline Earth Metal Ion Complexation on Amino Acid Zwitterion Stability: Results from Infrared Action Spectroscopy. J Am Chem Soc 2008; 130:6463-71. [DOI: 10.1021/ja711343q] [Citation(s) in RCA: 147] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Matthew F. Bush
- Department of Chemistry, University of California, Berkeley, California 94720-1460, and FOM Institute for Plasma Physics “Rijnhuizen”, Edisonbaan 14, 3439 MN Nieuwegein, The Netherlands
| | - Jos Oomens
- Department of Chemistry, University of California, Berkeley, California 94720-1460, and FOM Institute for Plasma Physics “Rijnhuizen”, Edisonbaan 14, 3439 MN Nieuwegein, The Netherlands
| | - Richard J. Saykally
- Department of Chemistry, University of California, Berkeley, California 94720-1460, and FOM Institute for Plasma Physics “Rijnhuizen”, Edisonbaan 14, 3439 MN Nieuwegein, The Netherlands
| | - Evan R. Williams
- Department of Chemistry, University of California, Berkeley, California 94720-1460, and FOM Institute for Plasma Physics “Rijnhuizen”, Edisonbaan 14, 3439 MN Nieuwegein, The Netherlands
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Zhao L, Guo W, Yang T, Lu X. Theoretical survey of the potential energy surface of methyl nitrite + Cu+ reaction. J Phys Chem A 2008; 112:533-41. [PMID: 18161951 DOI: 10.1021/jp075007i] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The gas-phase reaction of methyl nitrite with Cu+ has been investigated using density functional theory. The geometries and energies of all the stationary points involved in the reaction have been investigated at the B3LYP/6-311+G(2df,2pd) level. Seven different structures of the encounter complexes could be formed when Cu+ attacking at different electronegative heteroatoms of trans and cis conformational isomers of methyl nitrite, in which the inner oxygen attacks account for the most stable complexes. Extensive conversions could take place for these complexes converting into each other. Various mechanisms leading to the loss of NO and HNO are analyzed in terms of the topology of the potential energy surface. The reaction proceeds exclusively from the inner oxygen attachments, followed by four different mechanisms, i.e., direct dissociation, direct H abstraction, N-O activation, and C-H activation, where the former two provide direct channels for the respective losses of NO and HNO, the third one accounts for both of the losses, and C-H activation is unlikely to be important due to the energetics.
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Affiliation(s)
- Lianming Zhao
- College of Physics Science and Technology, China University of Petroleum Dongying, Shandong 257061, PR China
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Jover J, Bosque R, Sales J. A comparison of the binding affinity of the common amino acids with different metal cations. Dalton Trans 2008:6441-53. [DOI: 10.1039/b805860a] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Rimola A, Rodríguez-Santiago L, Ugliengo P, Sodupe M. Is the Peptide Bond Formation Activated by Cu2+ Interactions? Insights from Density Functional Calculations. J Phys Chem B 2007; 111:5740-7. [PMID: 17469869 DOI: 10.1021/jp071071o] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The catalytic role that Cu(2+) cations play in the peptide bond formation has been addressed by means of density functional calculations. First, the Cu(2+)-(glycine)2 --> Cu(2+)-(glycylglycine) + H2O reaction was investigated since mass spectrometry low collision activated dissociation (CAD) spectra of Cu(2+)-(glycine)2 led to the elimination of a water molecule, which suggested that an intracomplex peptide bond formation might have occurred. Results show that this intracomplex condensation is associated to a very high free energy barrier (97 kcal mol(-1)) and reaction free energy (66 kcal mol(-1)) because of the loss of metal coordination during the reaction. Second, on the basis of the salt-induced peptide formation theory, the condensation reaction between two glycines was studied in aqueous solution using discrete water molecules and the conductor polarized continuum model (CPCM) continuous method. It is found that the synergy between the interaction of glycines with Cu(2+) and the presence of water molecules acting as proton-transfer helpers significantly lower the activation barrier (from 55 kcal/mol for the uncatalyzed system to 20 kcal/mol for the Cu(2+) solvated system) which largely favors the formation of the peptide bond.
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Affiliation(s)
- A Rimola
- Departament de Química, Universitat Autonoma de Barcelona, Bellaterra 08193, Spain
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11
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Buchmann W, Spezia R, Tournois G, Cartailler T, Tortajada J. Structures and fragmentations of cobalt(II)-cysteine complexes in the gas phase. JOURNAL OF MASS SPECTROMETRY : JMS 2007; 42:517-26. [PMID: 17323419 DOI: 10.1002/jms.1183] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The electronebulization of a cobalt(II)/cysteine(Cys) mixture in water/methanol (50/50) produced mainly cobalt-cationized species. Three main groups of the Co-cationized species can be distinguished in the ESI-MS spectrum: (1) the cobalt complexes including the cysteine amino acid only (they can be singly charged, for example, [Co(Cys)n- H]+ with n = 1-3 or doubly charged such as [Co + (Cys)2]2+); (2) the cobalt complexes with methanol: [Co(CH3OH)n- H]+ with n = 1-3, [Co(CH3OH)4]2+; and (3) the complexes with the two different types of ligands: [Co(Cys)(CH3OH) - H]+. Only the singly charged complexes were observed. Collision-induced dissociation (CID) products of the [Co(Cys)2]2+, [Co(Cys)2 - H]+ and [Co(Cys) - H]+ complexes were studied as a function of the collision energy, and mechanisms for the dissociation reactions are proposed. These were supported by the results of deuterium labelling experiments and by density functional theory calculations. Since [Co(Cys) - H]+ was one of the main product ions obtained upon the CID of [Co(Cys)2]2+ and of [Co(Cys)2 - H]+ under low-energy conditions, the fragmentation pathways of [Co(Cys) - H]+ and the resulting product ion structures were studied in detail. The resulting product ion structures confirmed the high affinity of cobalt(II) for the sulfur atom of cysteine.
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Affiliation(s)
- William Buchmann
- Laboratoire Analyse et Modélisation pour la Biologie et l'Environnement (LAMBE), Université d'Evry-Val d'Essonne, CNRS UMR 8587, Bât. Maupertuis, Bd. F. Mitterrand, 91025 Evry Cedex, France.
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Grégoire G, Gaigeot MP, Marinica DC, Lemaire J, Schermann JP, Desfrançois C. Resonant infrared multiphoton dissociation spectroscopy of gas-phase protonated peptides. Experiments and Car–Parrinello dynamics at 300 K. Phys Chem Chem Phys 2007; 9:3082-97. [PMID: 17612732 DOI: 10.1039/b618094a] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The gas-phase structures of protonated peptides are studied by means of resonant infrared multiphoton dissociation spectroscopy (R-IRMPD) performed with a free electron laser. The peptide structures and protonation sites are obtained through comparison between experimental IR spectra and their prediction from quantum chemistry calculations. Two different analyses are conducted. It is first supposed that only well-defined conformations, sufficiently populated according to a Boltzmann distribution, contribute to the observed spectra. On the contrary, DFT-based Car-Parrinello molecular dynamics simulations show that at 300 K protonated peptides no longer possess well-defined structures, but rather dynamically explore the set of conformations considered in the first conventional approach.
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Affiliation(s)
- G Grégoire
- Laboratoire de Physique des Lasers UMR 7538 Institut Galilée, Université Paris 13, Villetaneuse, France.
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Corral I, Mó O, Yáñez M, Salpin JY, Tortajada J, Moran D, Radom L. An Experimental and Theoretical Investigation of Gas-Phase Reactions of Ca2+ with Glycine. Chemistry 2006; 12:6787-96. [PMID: 16807970 DOI: 10.1002/chem.200600127] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The gas-phase reactions between Ca(2+) and glycine ([Ca(gly)](2+)) have been investigated through the use of mass spectrometry techniques and B3-LYP/cc-pWCVTZ density functional theory computations. The major peaks observed in the electrospray MS/MS spectrum of [Ca(gly)](2+) correspond to the formation of the [Ca,C,O(2),H](+), NH(2)CH(2) (+), CaOH(+), and NH(2)CH(2)CO(+) fragment ions, which are produced in Coulomb explosion processes. The computed potential energy surface (PES) shows that not only are these species the most stable product ions from a thermodynamic point of view, but they may be produced with barriers lower than for competing processes. Carbon monoxide is a secondary product, derived from the unimolecular decomposition of some of the primary ions formed in the Coulomb explosions. In contrast to what is found for the reactions of Ca(2+) with urea ([Ca(urea)](2+)), minimal unimolecular losses of neutral fragments are observed for the gas-phase fragmentation processes of [Ca(gly)](2+), which is readily explained in terms of the topological differences between their respective PESs.
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Affiliation(s)
- Inés Corral
- Departamento de Química, C-9, Universidad Autónoma de Madrid, Cantoblanco, 28049-Madrid, Spain
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Antoine R, Tabarin T, Broyer M, Dugourd P, Mitrić R, Bonacić-Koutecký V. Optical Properties of Gas-Phase Tryptophan-Silver Cations: Charge Transfer from the Indole Ring to the Silver Atom. Chemphyschem 2006; 7:524-8. [PMID: 16463332 DOI: 10.1002/cphc.200500495] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We present a joint experimental and theoretical investigation of the electronic excitation spectra of the tryptophan-silver complex. The photodissociation spectrum of gas-phase [Trp-Ag]+ was measured from 215 to 330 nm using a quadrupole ion trap coupled to an optical parametric-oscillator laser. The calculated time-dependent density functional theory (TD-DFT) absorption spectra for different prototypes of structures are presented. Low-energy transitions that are experimentally observed are only calculated for the charge-solvation (CS) structures. These transitions are a signature of the metal-pi interaction in [Trp-Ag]+. The recorded spectrum is compared to a Boltzmann average of the absorption spectrum obtained from direct molecular dynamics (MD) simulations involving simultaneous transitions to excited states based on semiempirical configuration interaction (CI) calculations. The results demonstrate that charge transfer can be photoinduced from the indole ring to the silver atom.
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Affiliation(s)
- Rodolphe Antoine
- Laboratoire de Spectrométrie Ionique et Moléculaire, UMR 5579 (Université Lyon I et CNRS), 43 Bd du 11 Novembre 1918, 69622 Villeurbanne cedex (France)
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Abirami S, Wong CCL, Tsang CW, Ma NL. Dissociation of Alkaliated Alanine in the Gas Phase: The Role of the Metal Cation. Chemistry 2005; 11:5289-301. [PMID: 15995998 DOI: 10.1002/chem.200400816] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The dissociation of prototypical metal-cationized amino acid complexes, namely, alkaliated alanine ([Ala+M]+, M+ = Li+, Na+, K+), was studied by energy-resolved tandem mass spectrometry with an ion-trap mass analyzer and by density functional theory. Dissociation leads to formation of fragment ions arising from the loss of small neutrals, such as H2O, CO, NH3, (CO+NH3), and the formation of Na+/K+. The order of appearance threshold voltages for different dissociation pathways determined experimentally is consistent with the order of critical energies (energy barriers) obtained theoretically, and this provides the necessary confidence in both experimental and theoretical results. Although not explicitly involved in the reaction, the alkali metal cation plays novel and important roles in the dissociation of alkaliated alanine. The metal cation not only catalyzes the dissociation (via the formation of loosely bound ion-molecule complexes and by stabilizing the more polar intermediates and transition structures), but also affects the dissociation mechanisms, as the cation can alter the shape of the potential energy surfaces. This compression/expansion of the potential energy surface as a function of the alkali metal cation is discussed in detail, and how this affects the competitive loss of H2O versus CO/(CO+NH3) from [Ala+M]+ is illustrated. The present study provides new insights into the origin of the competition between various dissociation channels of alkaliated amino acid complexes.
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Affiliation(s)
- Seduraman Abirami
- National Institute of Education, Science and Technology Education, 1 Nanyang Walk, 637616, Singapore
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Constantino E, Rimola A, Rodríguez-Santiago L, Sodupe M. Coordination properties of glycylglycine to Cu+, Ni+ and Co+. Influence of metal cation electronic configuration. NEW J CHEM 2005. [DOI: 10.1039/b512618e] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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